In my environment I'm dealing with network topology, first terminnoogy:
The Verification Environment composed of DUT,Channels,Connections - each connection transmits packets via channels to the DUT.

The problem is how to control the packet attributes(i.e, pkt_color, pkt_size) in a flexiable way.
I take those attributes as an simplified example.

I would like to constraine those attributes by hirearchical constraints, I hope  the example below clarify the problem:


//Testcase test_1 (two hirearchies only)

//Topology: 1 channel, 3 connections{0,1,2}
//All packets(exclude connection #0 are constrained according to:
//   pkt_size dist {100:=1,𖒤:500]/=5, 1000:2}
//   pkt_color dist {GREEN:=19, RED:=1}
// Connection #0 packets are constrained according to:
//   pkt_size dist {500:=1, 1500:2}
//   pkt_color dist {GREEN:=1, RED:=0}

constraint connection::pkt_size_C
 {
   pkt_size dist {100:=1,𖒤:500]/=5, 1000:2}
   pkt_color dist {GREEN:=19, RED:=1}
 }

constraint connection::connection_global_c                     //why cant I use if(..)begin..end block  (Questa 6.2ie)
 {
         if (con_id==0) 
            pkt_size dist {500:=1, 1500:2}
         if (con_id==0) 
            pkt_color dist {GREEN:=1, RED:=0}
  }




Output    

<0>  gen_pkts: con_id #0 Generates 3 Packets
# <0>  printme: Packet generated - pkt_size=500
# <0>  printme: Packet generated - pkt_size=1500
# <0>  printme: Packet generated - pkt_size=1500
# <0>  gen_pkts: con_id #1 Generates 3 Packets
# <0>  printme: Packet generated - pkt_size=100
# <0>  printme: Packet generated - pkt_size=350
# <0>  printme: Packet generated - pkt_size=1000
# <0>  gen_pkts: con_id #0 Generates 3 Packets
# <0>  printme: Packet generated - pkt_size=500
# <0>  printme: Packet generated - pkt_size=700
# <0>  printme: Packet generated - pkt_size=650